MAL-2026-12740 Malicious code in devplatform-react-rest-client (npm)

On require of this package, index.js loads ext.js, which fetches a platform-specific binary from a rotating list of Cloudflare workers.dev hosts assembled at runtime via array.join to defeat static string scanning (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT chunked fallback channel via *.dl.wel1.ru (sdk, ext, pkg, net). The fetched binary is written to /tmp or %TEMP% under a cover-story name impersonating.NET diagnostics tooling (dotnet_diag<hex>.exe on Windows,.cache_<hex> on POSIX), chmod 0755 on POSIX, and spawned detached via /bin/sh -c or cmd.exe. Any consumer that requires the package on install/import receives arbitrary attacker-controlled code execution on the host.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.